I have a lipo battery, 11.1v, 2200mah, 20C. I needed to connect to to a smaller wire because the thing I am connecting it to has a little jst connector.

So I bodgily just wired the thick wire to the thin wire and plugged it in - All works perfectly fine.

The problem is, when using it continuously the thin wire gets warm and after about a minute it gets hot.

Now I wouldnt be running it continuously like that anyway out of testing, only in bursts. But I am worried because you know, lipos are fire hazards and hot wires just arent something I am comfortable having going on.

My question is what can I do to stop the heat problem?

I thought of just rewiring the gel ball blaster with thicker wires, but that seems like the longest way to fix this.

I thought about unsoldering the thick wires from the battery and soldering the thin ones to it, but would they get hot that way? (Im new to electronics xD) I dont want to do it and the battery catches fire in my hands haha.

The other thing I was thinking, maybe someone knows of some sort of connector that is made for connecting thick wires with thin ones and restricting the current or whatever happens so the small wire doesnt get hot.

One thing I should have done before asking is check if the wires on the original smaller battery get hot with extended use. I doubt it but you never know with chinese engineering xD

Anyways I look forward to your answers and welcome myself to this community : D

P.S I tried to upload photos but I am using my phone and it says they are too large for the forum. I will try to find a way to resize then upload afterward.

enter image description here

  • \$\begingroup\$ Welcome to EE Stack Exchange! Beep boop boop beep boop. \$\endgroup\$
    – K H
    Jan 10, 2019 at 0:58
  • \$\begingroup\$ If this is a device you created yourself, you should take it apart and increase the guage of those wires. If it's repurposed tech, you may need to do the same, but be aware that many battery operated devices that are not designed to operate while charging will heat up if provided with full charged voltage indefinitely. The device may be expected to decrease power level rapidly as voltage falls off at the start of the discharge cycle. If you've upgraded the battery pack, you may be affecting this as well as providing lower than expected resistance. Best course of action is to upgrade wire. \$\endgroup\$
    – K H
    Jan 10, 2019 at 1:03

2 Answers 2


Well I couldnt find this forum again sadly before I went ahead and desoldered the thick wires yesterday on the lipo and added thin ones of the same gauge as the original battery.

Turns out the heat problem is gone and everything seems to be working fine. The old battery was an 11.1v too, just less mah. (Like 1000 less)

Anyway I dont know how dangerous it is to do what I just did, probably wouldnt recommend it to anyone just in case but it all seems to be working just the same but without the heat problem, ran it for two minutes continuously and no heat at all.

Thanks for sharing your knowledge guys, I learned a bit today, if the battery catches fire or explodes or I die I will be sure to let you guys know how it goes in a few weeks, just in case anyone else wondering gets the idea to do something similar they will know what the longterm result is.

  • \$\begingroup\$ Just don't draw more current from the battery than the smallest wire can handle. Weakest link. \$\endgroup\$
    – DKNguyen
    Apr 30, 2020 at 23:16

For a given wire dimensions and a given current, the temperature rise is going to be the same regardless of "who" is supplying the current. If your new LiPo pack is the same voltage as the old, then it's not because you're using bigger batteries.

So, you may be stuck.

Things you can try:

  • Use a really short stretch of thin wire, just enough to make the connector work. This will generate as much heat per mm (or inch, your choice) as a longer chunk of wire, but that heat will be conducted to the thicker wire where it will (hopefully) get dissipated better.
  • Figure out a testing method that doesn't run things for any longer than your end use. Pulsing current through components (like wires) at higher levels than they can stand continuously is a done thing, although you want to be careful.
  • Use the thickest possibly wire that you can with that bitty little JST connector.
  • If the old pack was a 2S pack, see if you can do what you want with a bigger 2S pack.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.